Not applicable.
Not Applicable.
The invention relates generally to surgical tools for displacing and positioning organs during surgery, and to methods pertaining thereto. More particularly, this invention relates to a device for retracting and supporting the heart during cardiac surgical procedures.
Many patients with cardiac heart disease are often unable to treat their symptoms by dietary regulation or with drug treatments alone. One reason is that these non-invasive techniques may be inadequate to treat the severity of their condition. In some cases, there are no known drugs available that target the patient""s specific needs. For these patients, invasive surgery remains the most effective treatment option.
Open heart surgeries are often employed to treat heart disease, and most often to reestablish blood supply to the heart muscle itself. The main purpose of most heart surgeries is to graft replacement vessels around blockages in what is commonly known as a coronary artery bypass graft (CABG) procedure. In certain situations, open heart surgery is required to either excise or replace a portion of the heart, such as in mitral valve repair or replacement.
All of these invasive surgical techniques require access to the heart. Typically, access is gained from a full sternotomy involving the forcible spreading apart of the sternal cavity, and entry into the pericardium. Other preferred ways of obtaining access include partial sternotomies, and thoracotomies, which involve minimal incisions and partial removal of the ribs to provide access to the underlying heart. Once inside the pericardium, the heart needs to be retracted and repositioned so that the surgeon can reach the target site where blockage or damage has occurred. Thus, manual manipulation and repositioning of the heart is usually necessary to reach the surgical site.
In coronary bypass operations, for example, graft vessels can be anastomosed to the anterior descending artery, the circumflex artery and the posterior descending artery. Whereas the anterior descending artery lies on the front surface of the heart and is easily accessible to the surgeon, the circumflex and posterior descending arteries lie on the back surface of the heart and are reached only with additional help from assistants or devices. Thus, bypass operations are especially difficult because of the inaccessibility of the field of operation on the lateral and posterior sides of the heart.
Several methods have conventionally been used to achieve the required exposure. Ordinarily a surgical assistant is employed to manually lift and rotate the heart. This scenario can poses several problems. The assistant""s hand can get in the way of the operative field, and the assistant, who often stands adjacent to the surgeon, may restrict the surgeon""s movements. It is also difficult to keep the heart in a steady position. This form of manual manipulation is not only cumbersome but extremely tiring for both the assistant and the surgeon. In addition, manually handling the heart can cause bruising of the muscle and damage to the surrounding tissue.
Currently available manipulators and retractors for positioning either a stopped or beating heart to facilitate surgical access suffer from several drawbacks. Tools such as inflatable cushions and gauze pads that are used to shim organs into position present problems such as the risk that the tools will inadvertently be left behind after the procedure is complete, risk of damage to the surface of the heart or pericardium during their placement and removal, and lack of ability to control and readjust organ elevation and position. Furthermore, these inflatable cushions, or balloons, and gauze pads are difficult to place and remove when using minimal incisions. Other available tools include rigid manipulators with sharp contact points that can cause tissue trauma during intricate surgical movements.
Presently, a common method of manipulating the heart involves using simple strands or loops of umbilical tape placed in various positions around the heart to facilitate repositioning. However, these tapes are floppy and lack structure or foundation for subsequent manipulation. Another conventional method requires placing sutures through the pericardial tissue and then pulling on the suture strands to gain access to the lateral and posterior sides of the heart. But such a method renders possible tearing or damaging the pericardial tissue as the suture strands are tugged and pulled.
The heart muscle and its surrounding membrane are delicate tissues. Any trauma to this surface, or to the heart itself, can subsequently cause adhesions to form, and therefore any means of manipulation or retraction must be very gentle. There is presently an unfulfilled need for devices that will permit atraumatic manipulation and stabilization of a beating or stopped heart or organ to facilitate exposure of all surfaces of the heart or organ during surgery, so the surgeon can effect organ manipulation and positioning from outside the surgical cavity in a simplified and standardized manner.
The present invention overcomes the drawbacks inherent in prior art surgical methods and devices by providing a stable platform for retraction tape positioning of a beating or stopped heart during cardiac surgery, thus allowing for more consistent placement and easier retraction. In efforts to expose the various posterior and lateral surfaces of the heart during a thoracotomy or sternotomy, the present device allows the surgeon to place soft fabric tapes having an anchoring point around the apex of the heart and/or through the transverse sinus. Placing the stable platform underneath the heart provides the surgeon with a posterior pivot point with which he can gain access to the posterior and lateral regions. By simply applying tension to the tape, the surgeon is able to access these regions in a safe and efficient manner.
In one embodiment of the present invention, the surgical retraction and positioning device comprises a stable platform and a flexible tape attached thereto. The stable platform has an elongate body having a curved handle extending into an organ contacting base. The base is formed at the distal end of the handle and is at least partially concave to conform to the contours of the outer surface of the heart. A portion of a flexible element, such as umbilical tape, is secured to the base, leaving at least one free end for the surgeon to wrap, or secure, the heart against the organ contacting base.
In another embodiment, the organ contacting base also includes at least one laterally extending lobe. However, the organ contacting base can also include two laterally extending lobes, with each lobe extending in opposite, or different directions. The lobes can be concavely curved such that the organ contacting base cradles the heart. In another aspect of the present invention, one of the laterally extending lobes can be longer than the other lobe. The different designs of the organ contacting base provide the surgeon with the ability to support the heart in various positions while preventing blockage of specific target areas on the underside of the heart muscle.
The elongate body, or stable platform, can be formed of either a rigid or semi-rigid biocompatible material. Suitable materials include injection-molded plastics, shape-memory polymers, polymer composites, malleable metals, shape-memory metals, and metal alloys. The body can also be integrally formed. The handle can be at least partially convex, or have an S-shaped curve. The proximal end of the handle is adapted to be manually held, or secured to an external surgical retractor.
The flexible element attached to the organ contacting base can be either umbilical tape, or surgical grade fabric, ribbon, or cord. The flexible element must be able to conform to the outer surface of the heart when passed beneath or around the apex of the heart to secure the organ to the base. The end of the flexible element, along with the handle of the device, allows the surgeon to manipulate the heart""s position and orientation during surgery.
Although the invention is described mainly in terms of cardiac surgical techniques and the need for atraumatic positioning and manipulation devices, it is clear that need for such devices also exists in surgical procedures in other anatomic locations. For example, procedures that require lifting or positioning of solid organs including the liver and the spleen would be enhanced by the present invention.
Further features of the invention, its nature and various advantages, will be more apparent from the accompanying drawings and the following detailed description of the drawings and the preferred embodiments.